|Pos|No|Driver|Constructor|Laps|Time/Retired|Grid|
|---|---|---|---|---|---|---|
|1|12|Clay Regazzoni|Ferrari|60|1:01:25.34|3|
|2|4|Patrick Depailler|Tyrrell-Ford|60|+ 0:08.35|5|
|3|2|Jochen Mass|McLaren-Ford|60|+ 0:15.44|4|
|4|5|Ronnie Peterson|Lotus-Ford|60|+ 0:40.14|10|
|5|18|John Watson|Surtees-Ford|60|+ 0:45.55|6|
|6|8|Carlos Pace|Brabham-Ford|60|+ 0:45.90|7|
|7|16|Tom Pryce|Shadow-Ford|60|+ 0:46.66|8|
|8|24|James Hunt|Hesketh-Ford|59|+ 1 Lap|11|
|9|31|Chris Amon|Ensign-Ford|59|+ 1 Lap|9|
|10|21|Jacques Laffite|Williams-Ford|59|+ 1 Lap|13|
|11|9|Vittorio Brambilla|March-Ford|58|+ 2 Laps|12|
|12|22|Rolf Stommelen|Hill-Ford|58|+ 2 Laps|14|
|13|35|Tony Trimmer|Maki-Ford|54|+ 6 Laps|16|
|NC|20|Jo Vonlanthen|Williams-Ford|51|+ 9 Laps|15|
|Ret|17|Jean-Pierre Jarier|Shadow-Ford|33|Transmission|1|
|Ret|1|Emerson Fittipaldi|McLaren-Ford|6|Clutch|2|

Question: how many drivers participated in the race?
Answer: 16